The entire disclosure of Japanese Patent Application No. 2011-059798, filed Mar. 17, 2011, is expressly incorporated by reference herein.
1. Technical Field
The present invention relates to a device-mounted substrate including a through electrode, an infrared light sensor and a through electrode forming method.
2. Related Art
In a three-dimensional mounting package, a plurality of chips (device-mounted substrates) is vertically stacked to become one package, to thereby make it possible to reduce an occupation area. Thus, by using a through electrode which uses a via hole which is vertically formed through chips such as silicon wafers or dies, the wafers or dies are electrically connected with each other in the vertical direction.
Such a chip including the through electrode includes a semiconductor substrate and the through electrode formed in the semiconductor substrate. In the chip, since the semiconductor substrate has a specific electric potential with respect to a circuit formed on the semiconductor substrate and has an electric potential difference with respect to the through electrode which is electrically conductive with the circuit, a leakage current may occur between the through electrode and the semiconductor substrate. Thus, in JP-A-2010-177237, in order to prevent a leakage current, a resin insulating layer is formed between a through electrode and a substrate, and between an electrode connected with the through electrode and the substrate.
However, in a case where fine through electrodes of a high aspect ratio are formed by using the resin insulating layer, it is difficult to form the resin insulating layer with a sufficient thickness, thereby lowering the insulation function of the resin insulating layer.